[catlikesshrimp]

If you cover your phone with an antielectrostatic bag it can't communicate; that is a Faraday cage.

Since people around you will think you are also wearing a tinfoil hard, you had better stick to the phones with hardware switches as sibling comment mentions

[kube-system]

Most of those bags are total BS

[mulmen]

Seems easy to verify with an iPhone. Put it in the bag, transport the phone, look it up on Find My.

[kube-system]

Even easier, put any phone in the bag, call it. Does it ring? IME, yes.